摘要
由于半波长输电线路较长,常规的差动保护要经过通道传输时间延时动作,严重影响保护的速动性。该文提出一种适用于半波长线路的假同步差动保护,采用本侧数据与对侧一个周波前的数据进行同步,计算差动。假同步差动保护利用时差法估算故障点位置;以故障点为差动点,通过线路两端的电压、电流计算差动点两侧的电压、电流;以本侧电流和对侧一个周波前的电流分别计算到差动点处的电流进行差动,得到的差动电流作为分母,本侧电压计算到差动点处的电压作为分子,计算假同步差动阻抗,通过假同步差动阻抗的大小判断区内外故障。假同步差动保护由闭锁式、测距式和允许式假同步差动保护构成,分别对应保护线路的近段、中段和远段故障。在RTDS仿真软件上搭建半波长线路模型,对假同步差动保护进行仿真验证,结果表明假同步差动保护可以提高保护的动作速度,具有良好的动作性能。
Because the half-wavelength transmission line is longer than conventional lines, traditional differential protection operates after channel transmission time delay, which affects the speed of protection seriously. This paper proposed the false synchronization differential protection for half-wavelength transmission line, which used the data of one side and the data of the other side before a cycle constitute synchronization differential protection. False synchronization differential protection uses time difference method to estimate the short circuit point location. The short circuit point is the differential point, the voltage and current of both sides of the point can be calculated by the voltage and current of both ends of line. Using the current of one end and the current of the other end before a cycle calculate the current of both sides of the point, the sum of both sides current is the differential current. The voltage calculated by the voltage of one end is molecule, and the differential current is denominator to obtain the false synchronization differential impedance. Inside or outside fault is distinguished by the size of the false synchronization differential impedance. False synchronization differential protection is constituted by blocking type, ranging type and permissive type false synchronization differential protection, corresponding protection the fault near section, middle section and far section of half-wavelength transmission line. The simulation system of half-wavelength AC transmission line was established on RTDS, and the false synchronization differential protection was simulated and verified. Results show that the false synchronization differential protection can speed up the operation of protection, and has the excellent operation performance.
作者
周泽昕
柳焕章
郭雅蓉
杜丁香
王德林
ZHOU Zexin LIU Huanzhang GUO Yarong DU Dingxiang WANG Delin(China Electric Power Research Institute, Haidian District, Beijing 100192, China Central China Grid Company Limited, Wuhan 430077, Hubei Province, China China National Electric Power Dispatch and Control Center, Xicheng District, Beijing 100031, China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2016年第24期6780-6787,共8页
Proceedings of the CSEE
关键词
半波长线路
假同步
差动保护
时差法
half-wavelength line
false synchronization
differential protection
time difference method
